All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. This chapter discusses the protection which the law affords to unregistered trade marks through the tort of passing off. It covers the definition of passing off; the relationship between passing off and unfair competition; the elements of passing off; and defences to passing off (delay or acquiescence, bona fide use of the defendant’s own name, and concurrent use).